diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-au1550.c | 130 |
1 files changed, 75 insertions, 55 deletions
diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c index cae9dc89d88..66a04c2c660 100644 --- a/drivers/i2c/busses/i2c-au1550.c +++ b/drivers/i2c/busses/i2c-au1550.c @@ -269,9 +269,13 @@ static int au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) { struct i2c_au1550_data *adap = i2c_adap->algo_data; + volatile psc_smb_t *sp = (volatile psc_smb_t *)adap->psc_base; struct i2c_msg *p; int i, err = 0; + sp->psc_ctrl = PSC_CTRL_ENABLE; + au_sync(); + for (i = 0; !err && i < num; i++) { p = &msgs[i]; err = do_address(adap, p->addr, p->flags & I2C_M_RD, @@ -288,6 +292,10 @@ au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) */ if (err == 0) err = num; + + sp->psc_ctrl = PSC_CTRL_SUSPEND; + au_sync(); + return err; } @@ -302,6 +310,61 @@ static const struct i2c_algorithm au1550_algo = { .functionality = au1550_func, }; +static void i2c_au1550_setup(struct i2c_au1550_data *priv) +{ + volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base; + u32 stat; + + sp->psc_ctrl = PSC_CTRL_DISABLE; + au_sync(); + sp->psc_sel = PSC_SEL_PS_SMBUSMODE; + sp->psc_smbcfg = 0; + au_sync(); + sp->psc_ctrl = PSC_CTRL_ENABLE; + au_sync(); + do { + stat = sp->psc_smbstat; + au_sync(); + } while ((stat & PSC_SMBSTAT_SR) == 0); + + sp->psc_smbcfg = (PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 | + PSC_SMBCFG_DD_DISABLE); + + /* Divide by 8 to get a 6.25 MHz clock. The later protocol + * timings are based on this clock. + */ + sp->psc_smbcfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8); + sp->psc_smbmsk = PSC_SMBMSK_ALLMASK; + au_sync(); + + /* Set the protocol timer values. See Table 71 in the + * Au1550 Data Book for standard timing values. + */ + sp->psc_smbtmr = PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \ + PSC_SMBTMR_SET_PU(15) | PSC_SMBTMR_SET_SH(15) | \ + PSC_SMBTMR_SET_SU(15) | PSC_SMBTMR_SET_CL(15) | \ + PSC_SMBTMR_SET_CH(15); + au_sync(); + + sp->psc_smbcfg |= PSC_SMBCFG_DE_ENABLE; + do { + stat = sp->psc_smbstat; + au_sync(); + } while ((stat & PSC_SMBSTAT_SR) == 0); + + sp->psc_ctrl = PSC_CTRL_SUSPEND; + au_sync(); +} + +static void i2c_au1550_disable(struct i2c_au1550_data *priv) +{ + volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base; + + sp->psc_smbcfg = 0; + sp->psc_ctrl = PSC_CTRL_DISABLE; + au_sync(); +} + /* * registering functions to load algorithms at runtime * Prior to calling us, the 50MHz clock frequency and routing @@ -311,9 +374,7 @@ static int __devinit i2c_au1550_probe(struct platform_device *pdev) { struct i2c_au1550_data *priv; - volatile psc_smb_t *sp; struct resource *r; - u32 stat; int ret; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -348,43 +409,7 @@ i2c_au1550_probe(struct platform_device *pdev) /* Now, set up the PSC for SMBus PIO mode. */ - sp = (volatile psc_smb_t *)priv->psc_base; - sp->psc_ctrl = PSC_CTRL_DISABLE; - au_sync(); - sp->psc_sel = PSC_SEL_PS_SMBUSMODE; - sp->psc_smbcfg = 0; - au_sync(); - sp->psc_ctrl = PSC_CTRL_ENABLE; - au_sync(); - do { - stat = sp->psc_smbstat; - au_sync(); - } while ((stat & PSC_SMBSTAT_SR) == 0); - - sp->psc_smbcfg = (PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 | - PSC_SMBCFG_DD_DISABLE); - - /* Divide by 8 to get a 6.25 MHz clock. The later protocol - * timings are based on this clock. - */ - sp->psc_smbcfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8); - sp->psc_smbmsk = PSC_SMBMSK_ALLMASK; - au_sync(); - - /* Set the protocol timer values. See Table 71 in the - * Au1550 Data Book for standard timing values. - */ - sp->psc_smbtmr = PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \ - PSC_SMBTMR_SET_PU(15) | PSC_SMBTMR_SET_SH(15) | \ - PSC_SMBTMR_SET_SU(15) | PSC_SMBTMR_SET_CL(15) | \ - PSC_SMBTMR_SET_CH(15); - au_sync(); - - sp->psc_smbcfg |= PSC_SMBCFG_DE_ENABLE; - do { - stat = sp->psc_smbstat; - au_sync(); - } while ((stat & PSC_SMBSTAT_DR) == 0); + i2c_au1550_setup(priv); ret = i2c_add_numbered_adapter(&priv->adap); if (ret == 0) { @@ -392,10 +417,7 @@ i2c_au1550_probe(struct platform_device *pdev) return 0; } - /* disable the PSC */ - sp->psc_smbcfg = 0; - sp->psc_ctrl = PSC_CTRL_DISABLE; - au_sync(); + i2c_au1550_disable(priv); release_resource(priv->ioarea); kfree(priv->ioarea); @@ -409,27 +431,24 @@ static int __devexit i2c_au1550_remove(struct platform_device *pdev) { struct i2c_au1550_data *priv = platform_get_drvdata(pdev); - volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base; platform_set_drvdata(pdev, NULL); i2c_del_adapter(&priv->adap); - sp->psc_smbcfg = 0; - sp->psc_ctrl = PSC_CTRL_DISABLE; - au_sync(); + i2c_au1550_disable(priv); release_resource(priv->ioarea); kfree(priv->ioarea); kfree(priv); return 0; } +#ifdef CONFIG_PM static int i2c_au1550_suspend(struct platform_device *pdev, pm_message_t state) { struct i2c_au1550_data *priv = platform_get_drvdata(pdev); - volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base; - sp->psc_ctrl = PSC_CTRL_SUSPEND; - au_sync(); + i2c_au1550_disable(priv); + return 0; } @@ -437,14 +456,15 @@ static int i2c_au1550_resume(struct platform_device *pdev) { struct i2c_au1550_data *priv = platform_get_drvdata(pdev); - volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base; - sp->psc_ctrl = PSC_CTRL_ENABLE; - au_sync(); - while (!(sp->psc_smbstat & PSC_SMBSTAT_SR)) - au_sync(); + i2c_au1550_setup(priv); + return 0; } +#else +#define i2c_au1550_suspend NULL +#define i2c_au1550_resume NULL +#endif static struct platform_driver au1xpsc_smbus_driver = { .driver = { |